Thoughts after 10 days with my Playbook:
It is slickly executed, but suffers from annoyances. It goes slowly at certain points, such as when you go into app world and click on the search box. It takes a while before the keyboard pops up. When you suspend it you don't know if a swipe will wake it up. There may be some logic to it, but I don't know what it is.
The app store, aka App World doesn't have a lot of what you want. For example, I couldn't find an app that acts as a satnav. The pricing is high too - $5 for angry birds, when it's less than $1 on the Apple app store. The online app store doesn't let you filter by device type, which seems to me to be crazy. When you create an app you specify which one of about 30 types of app it is, but you can't filter by those too.
There's no Adobe Digital Editions, which I was hunting for because I wanted to read ebooks from my library. However I did find the app from the company that manages ebooks for our county - Overdrive, and so that made me very happy - apart from the bugs in the app itself. It runs in the android emulator so it's probably hard to track down the cause of these bugs - the software, or the emulator itself.
I've released my second app, GPS to Grid Ref, which isn't rubbish, unlike my previous one. It is simple though - you click the button and it finds your position and displays it in UK Grid Reference format.